1. Field of the Invention
The present invention relates to electromagnetic relays, and in particular to so-called "flat" relays wherein a core leg extends axially through the coil winding.
2. Description of the Prior Art
Electromagnetic relays are known in the art having a coil body with a winding thereon and having a core yoke formed in one piece from a flat ribbon or tape stock with at least two legs, one core leg being plugged in the axial direction through the coil member and one yoke leg extending parallel to the coil axis either next to or above the coil winding. Such relays have a flat armature with one end mounted on a leaf spring at the free end of the yoke leg, and the other end forming an air gap opposite the free end of the core leg. The leaf spring is connected to the core yoke by a terminal element, and the free end extends beyond the moveable armature and functions as a contact spring in cooperation with at least one stationary cooperating contact element.
A relay as described above is disclosed in U.S. Pat. No. 3,781,729. In that relay, the core yoke is bent in a U-shape from a ribbon or flat tape, and the free end of the yoke leg, which is angled toward the exterior, carries a flat armature by means of a leaf spring. The flat armature forms a working air gap with the narrow end face of the core leg. The coil in this relay is mounted to a relay base only by means of the angled projection of the yoke leg. The base receives stationary contact elements at a side opposite therefrom. This structure makes tolerances between the armature, the core pole face, and the contact elements difficult to control, and relatively complicated adjustment of the various components is necessary in virtually every unit. Additionally, the arrangement of the coil in this relay, with an axis disposed perpendicularly with respect to the plane of the relay base, results in an unfavorable three dimensional structure, wherein a relatively wide housing having a large, but only partially used, interior volume is necessary.